The research in my laboratory is on the role played by the cerebellum in controlling posture and movement. One method will be to train monkeys to perform certain sterotyped movements of the limbs, and then to record with microelectrodes the discharge of single cerebellar neurons as the monkey performs the movement. Questions that will be asked during this grant period are: 1) Do cerebellar neurons control one physical aspect of movement at a joint as opposed to others - such as its start, stop, direction, velocity, displacement, or force? 2) Do cerebellar neurons control both gamma and alpha motor neurons? 3) During the learning of a movement, do cerebellar neurons fire in such a way as to support a current idea that one of the cerebellum's functions is to adapt new movements? A second method will be to ablate certain portions of the cerebellum thought to have a defined physiological function to see if that function alone is impaired. Questions to be asked are: 1) Does a small lesion affect movement at one joint and not others? 2) Does a small lesion affect one of the physical variables as opposed to others? 3) Does a lesion impair motor adapation more than motor performance? A third method of tracing nerve axonal pathways will address questions about the anatomical connections of cerebellar outflow raised by these studies.